Table of Contents
Advertisement
LANGER
DE-01728 Bannewitz
mail@langer-emv.de
EMV-Technik
www.langer-emv.com
2 Function
2.1 Method of measurement
An RF-immune probe (AS 100, AS 110, AS 120, AS 200, AS 300 or AS 350 optical fibre probe), of
which the A/D (analog-to-digital) converter is an integral part, is autonomously operated in the DUT
without interfering with the DUT's EMC conditions.
The only connection between the AS XXX probe and the DUT is an optical fibre that sends the
measured values, which are continuously generated by the ADC as a serial data flow, to an optical
receiver.
A D/A (digital-to-analog) converter (DAC) converts the digital sampling values back into an analog
signal that can be evaluated by an oscilloscope.
Figure 7 Optical fibre measuring system
2.2 AS XXX ADC probe (sensor)
The voltage that is applied to input E (Measuring input Figure 8) of the AS XXX probe (sensor) is
converted to a serial data flow by an A/D converter.
The variable voltage divider generates the following control ranges:
Optical fibre probe (sensor)
AS 100
AS 110
AS 120
AS 200
AS 300
AS 350
In the AS 120 optical fibre probe a capacitive coupled amplifier is integrated with a low cut-off
frequency of about 300 Hz. The sensor is protected against polarity reversal.
2.3 AE XXX DAC receiver
An optical receiver converts the optical fibre signal to a serial data signal. A sequential logic system
synchronizes the receiver and controls the serial-parallel conversion of the measured values and
the D/A conversion. Operational amplifiers are connected to the DAC output to filter and adjust the
control ranges.
A100 / A200 / A300
Control range
50 / 10 VDC
10 / 1 VDC
1 / 0.1 VAC
50 / 10 VDC
±10 VDC
±50 VDC
- 6 -
Advertisement
Table of Contents
